In artificial knee joint replacement surgery, a femoral component is fixed to the distal part of a femur of a patient, and a tibial component is fixed to the proximal part of a tibia of the patient. The femoral component has a convex surface, which is received by a concave surface of the tibial component. With this configuration, when the patient bends and extends the knee, the femoral component and the tibial component slide relative to each other while being in contact with each other, achieving smooth movement of the knee of the patient.
In the artificial knee joint replacement surgery, osteotomy is performed on the distal part of the femur. With this, the distal part of the femur is formed into a shape appropriate for installation of the femoral component. Furthermore, in the artificial knee joint replacement surgery, osteotomy is performed on the proximal part of the tibia. With this, the proximal part of the tibia is formed into a shape appropriate for installation of the tibial component. Various instruments are known as instruments for use in osteotomy (see Patent Documents 1 and 2, for example).
Also, the arrangement of the femoral component at the distal part depends on the orientation (angle) and the like of the section of the distal part to which the femoral component is to be fixed. Similarly, the arrangement of the tibial component at the proximal part depends on the orientation (angle) and the like of the section of the proximal part to which the tibial component is to be fixed. Also, the movable range of the knee joint in its bending motion, extending motion, medial/lateral rotation, and varus/valgus motion depends on the arrangement of the femoral component and the tibial component, and the like.